1. Field of the Invention
The present invention concerns electronic messaging in general and electronic mail in particular, and provides a method and system for handling electronic mail messages, verifying the origination of messages to determine the probability that they are or are not junk e-mail, and detecting that a mass mailing has been initiated by utilizing special addresses.
2. Description of the Background
Digital storage of information brings with it the ability to transfer such information easily and inexpensively. As a result of this situation, unwanted or unsolicited junk e-mail (sometimes referred to as xe2x80x9cspamxe2x80x9d) has become prevalent on the Internet since messages can be sent without a specific xe2x80x9cper-characterxe2x80x9d cost. As a result, the average e-mail account currently receives a number of unsolicited, unwelcome pieces of junk e-mail each day, with a rapidly increasing number of pieces being forecast.
Documents are available which describe electronic mail handling procedures. In particular, two Internet standards on e-mail are incorporated herein by reference in their entirety. They are: Internet STD0014 entitled xe2x80x9cMAIL ROUTING AND THE DOMAIN SYSTEMxe2x80x9d (also known as RFC 974) and Internet STD0010 entitled xe2x80x9cSIMPLE MAIL TRANSFER PROTOCOLxe2x80x9d (also known as RFC 821). The contents of the Second Edition of xe2x80x9csendmailxe2x80x9d by Bryan Costales and Eric Allman, published by O""Reilly Publishing, is also incorporated herein by reference. Further, some issued patents address the general handling of electronic mail. For example, U.S. Pat. No. 5,377,354 teaches a method for prioritizing a plurality of incoming electronic mail messages by comparing the messages with a list of key words. U.S. Pat. No. 5,619,648 teaches a method for reducing junk e-mail which uses non-address information and uses a filtering system that has access to models of the user""s correspondents. The e-mail system adds a recipient identifier that is used to further specify the recipients in the group to whom the message is sent who should actually receive the message.
U.S. Pat. No. 5,555,426 teaches a method and apparatus for disseminating messages to unspecified users in a data processing system. The method permits users to associate conditions of interest, such as keywords or originator identities, but does not perform any verification of the originator""s identity. The method permits messages to be sent based upon probable interest in the message, rather than being addressed to any specific individual.
U.S. Pat. No. 5,627,764 teaches a method for implementing a rules-based system that can run a user""s set of rules under system control and process messages according to the user""s rules. Peloria Mail Scout uses rules to screen junk mail by limiting messages to only known and acceptable senders, but makes no provision for unknown, yet acceptable senders.
U.S. Pat. No. 5,675,733 teaches a method for collecting, sorting, and compiling statistical summaries of message acknowledgment data, also known as Confirmations of Delivery or COD""s. The invention teaches a method for acknowledging a single message to multiple recipients and generating a statistical list of information delivery under such circumstances. Each of the above-referenced US Patents are incorporated herein by reference in their entirety.
It is an object of the present invention to address deficiencies in known e-mail handling systems.
This object and other objects of the present invention are addressed through the use of a computer system or mail handling system which provides enhanced blocking of junk e-mail. Accordingly, the present invention first ascertains if the sender of the e-mail has a verifiable identity and valid computer address. Based upon that determination, certain user-assignable and computable confidence ratios may be automatically determined. If the identity cannot be verified or the address is determined not to be valid or usable for a reply to the sender, the mail can be assigned a presumptive classification as junk e-mail. By applying additional filters, the confidence ratio can be increased to nearly 100%, and the mail can be handled in accordance with standard rules-based procedures, providing for a range of alternatives that include deletion or storage in a manner determined by the user.
The system of the present invention also advantageously utilizes a cooperative tool, known as an authenticator, to determine if a received e-mail is a junk e-mail. The mail handling system, either automatically or as part of a mail filter, contacts an authenticator with information about a received e-mail. If the authenticator has received negative or adverse notifications from other users who have received the same or similar e-mails, the authenticator informs any mail handling systems that ask that the received e-mail is very likely junk e-mail. This information from the authenticator along with other factors can be weighted to provide an overall confidence rating.
The system of the present invention also advantageously utilizes a list of xe2x80x9cseedxe2x80x9d addresses that do not correspond to real users but, rather, to special non-existent (or ghost) accounts. When a message is received that is addressed to a ghost account, the system searches other incoming and recently received messages for the same message body. For messages with the same message body as received for the ghost account, the system marks the messages as having a high probability of being junk e-mail. In an alternate embodiment, the system of the present invention provides cooperative filtering by sending the message body to authenticators or other systems to help the authenticators or other systems to determine that the message is probably a junk e-mail.